Effects of Bariatric Surgeries on Obesity and Comorbidities

to the editor: I was pleased to see the article on bariatric surgery. This is a very important and pertinent subject for primary care physicians. The article was excellent, and relatively comprehensive. However, some important issues were omitted.

Different bariatric procedures do not affect obesity and comorbidities similarly. Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) produce a metabolic effect and are the most powerful interventions for the treatment of diabetes mellitus. This contrasts with laparoscopic adjustable gastric banding (LAGB), which does not have a significant metabolic effect.

Because various bariatric procedures have different effects on obesity and comorbidities, there are significant differences in patient outcomes. Numerous large studies clearly demonstrate that RYGB produces superior results (especially in terms of resolution of diabetes) and greater weight loss compared with LAGB.1–3 In a meta-analysis of 135,246 patients, 80 percent of those who underwent RYGB or VSG had resolution of diabetes, compared with 57 percent of those who underwent LAGB.1 Resolution of comorbid conditions, such as hypertension, sleep apnea, dyslipidemia, and gastroesophageal reflux disease, is significantly higher after RYGB than after LAGB.3 Patients undergoing LAGB lose an average of 46 percent of excess body weight compared with 60 percent1,2 and up to 80 percent after RYGB.3

Data in Table 8 of the original article were taken from numerous sources (some from as long ago as 2004) and did not include long-term complication rates. Moreover, there was an extremely wide range of excess body weight lost after LAGB, and these amounts were not in agreement with more recent sources based on large numbers of patients.1–3

LAGB is associated with a high rate of long-term complications. In a recent study of 151 consecutive patients who underwent the procedure from 1994 to 1997, the reoperation rate was 60 percent, one-third of patients experienced band erosions, and approximately 50 percent required band removal.4

Because of heavy direct-to-consumer advertising, many patients are led to believe that LAGB is an easy and effective treatment. However, it is associated with inferior long-term outcomes compared with RYGB and VSG. Most patients who undergo RYGB have greater weight loss, increased resolution of diabetes, improved quality of life, short-term complication rates similar to LAGB, and a lower rate of late complications (reoperations). Overall, RYGB has a better risk-benefit profile than LAGB.5 Patients should be aware of the high failure rate of LAGB.

Physicians must be actively involved in obesity management, and should identify the most appropriate weight management options for each patient.6 Various surgical procedures have unique physiologic effects, resolution rates of comorbidities, and weight loss. Providing this information is a critical element of discussing, counseling, and preparing patients for bariatric surgery.

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This series is coordinated by Kenny Lin, MD, MPH, Associate Deputy Editor for AFP Online.